Mouse Embryo Resuscitation

Many factors can influence the time frame for the recovery of cryopreserved mouse embryos. This time frame represents the minimum time needed for the delivery of live mice from cryopreserved, pre-implantation, fertilized embryos.

Upon receipt of the necessary paperwork, a recovery timeline will be developed and provided to the investigator. The anticipated time frame from receipt of the frozen embryos to delivery of weaned pups is nine to twelve weeks.

The time needed for each of the stages of production is detailed below:

1-2 weeks

Upon receipt of the completed Cryopreserved Embryo Recovery request form, production animals will be ordered as needed. Once they are received, a two day acclimation period is required by OLAR.

2-3 weeks

Once the cryopreserved embryos are received, CD-1 females will be superovulated and bred to vasectomized CD-1 males to produce pseudopregnant foster females for embryo transfer. Cryopreserved embryos will be thawed according to the donor institution’s protocol, and surgically implanted into the pseudopregnant recipient female(s). The embryos will be transferred into either the oviduct of .5 dpc for one or two-cell embryos and into the uterus of 2.5 dpc for eight-cell embryos.

3-4 weeks

Litters will be born three weeks after the date of embryo transfer.

6-7 weeks

Litters will be weaned at 3 weeks of age. At that time, the foster female will be tested for mouse pathogens.

7-8 weeks

Test results on the foster female will be received and reviewed by OLAR.

8-9 weeks

Once the test results have been cleared by OLAR, the weaned mice are transferred to the investigator’s protocol.